Analysis of neutrino oscillation parameters in the light on quantum entanglement
Rajrupa Banerjee, Papia Panda, Rukmani Mohanta, Sudhanwa Patra
TL;DR
This work treats three-flavor neutrino oscillations as a tripartite quantum system and uses Entanglement of Formation and concurrence to quantify flavor-state entanglement within the DUNE setup. It verifies entanglement monogamy via the CKW inequality and identifies three energy windows where entanglement extrema occur, notably a global minimum at $E_\nu \approx 1.27$ GeV and a local minimum near $2.5$ GeV, with maximal $\nu_{\mu}$–$\nu_{\tau}$ entanglement and a nearly separable $\nu_e$. By extracting best-fit oscillation parameters at these extrema, the study shows entanglement can slightly reduce CP violation sensitivity while enhancing mass-hierarchy discrimination, and it identifies how entanglement-informed measurements can improve precision. Overall, entanglement considerations offer a principled lens for interpreting neutrino oscillations and guiding experimental strategy in long-baseline experiments.
Abstract
Numerous neutrino experiments have confirmed the phenomenon of neutrino oscillation, providing direct evidence of the quantum mechanical nature of neutrinos. In this work, we investigate the entanglement properties of neutrino flavor states within the framework of three-flavor neutrino oscillation using two major entanglement measures: entanglement of formation (EOF) and concurrence, utilizing the DUNE experimental setup. Our findings indicate that the maximally entangled state appears between $ν_μ$ and $ν_τ$ whereas, $ν_{e}$ behaves as a nearly separable state. To further explore the nature of bipartite entanglement, we introduce the concept of the monogamy of entanglement, which allows us to investigate the distinction between genuine three-flavor entanglement and bipartite entanglement. Our analysis confirms that the three-flavor neutrino system forms a bipartite entanglement structure, adhering to the Coffman-Kundu-Wootters (CKW) inequality. Additionally, we implement a minimization procedure to find the best-fit values of the oscillation parameters that correspond to the concurrence minima at the two specific energy points where the concurrence reaches its lowest values. Using these best-fit values, we probe three fundamental unknowns in neutrino oscillation: CP violation sensitivity, neutrino mass hierarchy, and the octant issue of $θ_{23}$, across two distinct energy points. Our results manifest that while the best-fit values obtained through concurrence minimization show slightly reduced sensitivity to CP violation compared to current best-fit values, they exhibit greater sensitivity to the mass hierarchy. Furthermore, the study reveals a maximal mixing angle for the atmospheric sector.